Problem: Evaluate the following expression when $d = 3$ and $c = 10$. $6$ $d$ $ + 5$ $c$ $ - 4$
Answer: Substitute $3$ for ${d}$ and $10$ for ${c}$ $ = 6{(3)} + 5{(10)} - 4 $ $ = 18 + 50 - 4 $ $ = 64$